swift-format lint is slower when run with the parallel option

[Frizlab]

time swift-format lint -rp . >/dev/null 2>&1
swift-format lint -rp . > /dev/null 2>&1  175.66s user 0.62s system 1496% cpu 11.782 total

time swift-format lint -r . >/dev/null 2>&1
swift-format lint -r . > /dev/null 2>&1  7.16s user 0.26s system 98% cpu 7.535 total

[allevato]

Out of curiosity, what's the total file count that it's trying to operate on?

If you could get an Instruments trace of what one of those runs looks like, that would also be really useful.

[Frizlab]

find . -name "*.swift" | wc -l -> 1905

I’ll try and get a trace.

[Frizlab]

There you go (I did with and without the -p option, the rest is exactly the same in both runs).

Traces.zip